Summertime heat will traverse the country through this weekend as a trough digs down into the western US, leading to a ridge of high pressure to the east. Early next week, a large area of high pressure will develop off the East Coast. Known as the ‘Bermuda High’ due to its location, it will pump heat and humidity up the coast and into the Northeast, allowing for potentially multiple days of high temperatures in the 90s.
This Wednesday, the heat will be situated over the western US before the trough that moves in this weekend. Much of the region will feel temperatures 5 to 15 degrees above average, but some locations in the intermountain West will be as warm as 35 degrees above normal. The only locations in the West that will be cooler than normal is the Pacific Northwest coast, where temperatures will generally be 5 to 10 degrees below average. Across the rest of the nation, it will be rather seasonable, with temperatures around 5 degrees within normal.
On Thursday, the effects of that trough will be felt as the heat shifts to the Plains. Now it’s the midsection of the country that will feel the high temperatures, specifically the Northern Plains where high temperatures may break records and reach levels of up to 30 degrees above normal. The remainder of the Central US can expect highs mainly up to 15 degrees above normal. To the east, temperatures will remain seasonable, although New York state and northern New England will be quite chilly with temperatures as much as 25 degrees below-average due to the cold front, which may bring severe storms on Wednesday. Temperatures will be variable across the West. Highs will be up to 15 degrees above average in the Southwest, while up to 10 degrees below-average in the Northwest.
Below normal temperatures will then dominate the western US on Friday thanks to the trough. Besides a sneaky area of warmth relative to average from the Sierra Nevada through the central Rocky Mountains, temperatures will generally be 5 to 10 degrees cooler relative to normal. The heat will continue to drift to the east. The warmest of temperatures compared to average will now shift to the Central Plains and Midwest. Highs will mainly be 10 to 15 degrees above average in these areas. Across the rest of the central third of the US, highs will be up to 10 degrees above average. The East Coast will remain seasonable — until this weekend.
This weekend, Father’s Day weekend, will become hot for the eastern US. A widespread area of temperatures 10 to 20 degrees above average will be commonplace across the Central Plains and Midwest once again. Nearly half of the nation is forecast to feel highs in the 90s on Saturday. The rest of the eastern two-thirds of the country will be several degrees warmer than average unless you’re along the Gulf Coast due to Invest 91L. That’s where highs will be seasonably cool. It will also be cooler than normal across the West thanks to the tropical moisture from Bud beginning to stream in. These clouds and showers associated with the remnants of then-Hurricane Bud will put on a lid on the temperatures.
Then on Sunday, highs in the upper 80s to the 90s will stream into the Northeast, which is generally 10 degrees above-average. To the west, the Midwest and Great Lakes will really be feeling the heat, with temperatures up to 25 degrees above-average. It will be quite difficult to not find high temperatures in the 90s east of the Continental Divide, unless you’re in the Dakotas and northern Minnesota. Meanwhile across the West, it will be a stark contrast with widespread high temperatures 5 to 15 degrees below normal.
This trough will continue to erode the warmth, this time in the Plains. Temperatures in this part of the US will be variable, with temperatures around 5 degrees within average on Monday. Despite this cool down, it will still be hot in many areas as it is summer after all. The only areas experiencing above-average temperatures in the West will be the Pacific Northwest. Meanwhile in the Northeast, the heat will dominate and peak in intensity for the region. Highs will be 5 to at least 15 degrees above-average. That translates to actual high temperatures in the low to mid 90s for many, including the major cities in the I-95 corridor. It will also be humid, with heat indexes rising into the 100s. Record highs will also be challenged, including the daily record high of 94 degrees in Boston. Our current forecast calls for a high temperature of 92 degrees. Across remaining areas, temperatures will closer to normal but it will be hot with highs in the 90s at most locations in the Southern Plains, Southeast, and Ohio River Valley.
Temperatures will begin to come back toward average nationwide as the week moves on. A cold front coming in from the north will continue to usher in cooler yet seasonable air to the Northern Tier, including northern portions of the Northeast. Temperatures will be up to 10 degrees above-average in the Mid-Atlantic. Much of the West will also remain cool, with highs mainly up to 10 degrees below average, except for the Pacific Northwest. Highs in this region will be up to 30 degree above-average due to a huge ridge over western Canada.